In portable electronic devices such as electronic notebooks, cellular phones, personal handyphone systems (PHS), digital cameras, music players, televisions, notebook personal computers, and game machines, adhesive tapes are used for fixing various members or modules, for example, for bonding a housing to a panel that protects an information display unit such as a liquid crystal display (LCD) or an organic electroluminescence display (OELD). Many of these portable electronic devices are provided with waterproofness. In such portable electronic devices, waterproofness is achieved by using an adhesive tape for fixing members.
For example, adhesive tapes that use a flexible foam as a base are disclosed as adhesive tapes having a waterproof performance (refer to PTL 1 and PTL 2). It is disclosed that since these adhesive tapes have small thicknesses and good followability, the adhesive tapes can be suitably used for providing portable electronic devices with waterproofness.
However, regarding recent portable electronic devices such as smartphones, tablet personal computers, notebook personal computers, and game machines, the screen size of an information display unit of such a portable electronic device has been increasing. In addition, there is a high demand for adhesive tapes that have small widths and that can fix protective panels of information display units or information display device modules for the purpose of improving the degree of freedom of the information display units. In the fixation of information display units having large screen sizes or panels that protect the information display units and in the fixation of protective panels or information display device modules using an adhesive tape having a small width, the above-described adhesive tapes become easily separated when an impact due to falling or the like is applied. Thus, an improvement in impact resistance has been desired.
PTL 1: Japanese Unexamined Patent Application Publication No. 2010-155969
PTL 2: Japanese Unexamined Patent Application Publication No. 2010-260880